Other mistake: In one of the opening scenes where the boys ride to the baseball game, the fishermen they pass make a rude comment towards them. In response, you hear Joe ring his bicycle bell and see them flip the men off. The bicycle has no bell.
Other mistake: In the second baseball scene, Joe is sitting on the bench next to one character with the number 8 and Simon, who is on Joe's other side is also number 8. Two players on the same team would not be the same number.
When Rebecca Wenteworth is walking towards the baseball diamond, she is looking behind her and waving. When she gets hit in the head with the ball, it's on the wrong side of the face. She should have been hit on the left side of the face.